1. Field of the Invention
The present invention relates to a forming die having an upper die member and a lower die member, which are constructed respectively by a plurality of segments and a managing method thereof.
2. Description of Related Art
A forming die for forming an insulation overcoat member of a polymer insulator, is constructed using a forming die having an upper die member and a lower die member each constructed respectively by a plurality of segments. FIG. 5 is a schematic view showing one embodiment of a known forming die. In the embodiment shown in FIG. 5, a forming die 51 comprised of an upper die member 52 and a lower die member 53 as illustrated, wherein the upper die member 52 and the lower die member 53 are constructed respectively by securing a plurality of segments 54 by mean of a tie-rod 55. Numeral 56 designates a cavity for forming a forming material such as silicone rubber into a predetermined shape.
Generally, installation or breaking down of the forming die 51 to a press apparatus is performed as follows. At first, ten pieces of the segments 54 are defined as one module of 0.6 m unit. The modules are transferred to the press apparatus in such a manner that a plurality of modules are arranged to form the lower die member 53 on the press apparatus. Then, in the same manner, a plurality of modules are arranged on the lower die member 53 one by one to form the upper die member 52. When all the segments 54 are arranged, the upper die member 52 and the lower die member 53 are respectively secured in an integral manner by means of the tie-rod 55. Subsequently, in order to install the forming die 51 to the press apparatus, the upper die member 52 is fixed to an upper platen of the press apparatus such that the upper and a lower ram heads are closed. Then, the lower die member 53 is fixed to a lower platen of the press apparatus.
Using the method described above, it is possible to assemble the forming die 51 having the upper die member 52 and the lower die member 53 each constructed by a plurality of segments 54 and to install the forming die 51 to the press apparatus. However, when forming a product having a length of 3 m or more the assembling operation of the forming die 51 and the installing operation of the forming die 51 to the press apparatus takes a long time. Moreover, it is necessary to perform the assembly and installation when the press apparatus is stopped. Therefore, equipment operation performance is lowered. In addition, in the assembled upper die member 52 and the assembled lower die member 53, a deviation between segments 54 is prevented only by the securing power of the tie-rod 55. Therefore, an up and down deviation and a right and left deviation between segments 54 sometimes does occur. If a product is formed by using such a forming die 51, a projection portion and a depression portion are generated on the formed product. In this case, it is necessary to repair such a projection or depression portion, or not to use the formed product as a complete product. Further, in order to eliminate the drawbacks mentioned above, it is sometimes necessary to re-assemble the forming die 51, thereby decreasing equipment operation performance again.